Here's another possibility. If your other NST still works you could make a backup with NookManager. Then write down the serial number and MAC address of the new one. Now use NookManager to "restore" the new one. So now it's registered. There is a post on the forum somewhere about editing MAC addresses so the two devices won't interfere with each other. Since you can't connect to B&N the serial number probably doesn't matter.
Yeah, good thought, unfortunately it's totally bricked, won't turn on at all.